Patent Application Publication of USP-2002/0005178 A1 discloses that a heat accumulating device is provided for executing warming-up of an engine of a vehicle prior to a engine start. The engine start is beforehand detected through opening and closing of a door or manipulation of an ignition key as a preparation operation to the engine start. The engine is then warmed up using the heat accumulating device prior to the engine start. Here, in particular, the engine start is prohibited until the warming-up is completed. The warming-up using the heat accumulating device is thereby securely executed.
However, failure of a function for detecting the preparation operation to the engine start naturally leads to incapability of detecting the preparation operation. Accordingly, the warming-up of the engine cannot be executed before the engine starts. Reducing emission thereby becomes difficult due to starting of the engine in low temperature.